Temperature and humidity control system



June 16, 1942. e. D. KINGSLAND 2,286,551

TEMPERATURE AND HUMIDITY CONTROL SYSTEM Filed Jan. 2, 1936 3 Sheets-Shee t 1 J1me cs. D. KINGSLAND 2,235,551

TEMPERATURE AND HUMIDITY CONTROL SYSTEM Filed Jan. 2, 1936 5 Sheets-Sheet 2 152 I5 Pimento? George D Kingslazzd 1 w WW June 16, 1942. G D NG ND 2,286,551

TEMPERATURE AND HUMIDITY CONTROL SYSTEM Filed Jan. 2, 1936 3 Sheets-Sheet 3 3maentor George D. [(251581 and Gttomeg TATES Patented June 16,1942

TEMPERATURE AND I I 4111:- CONTROL SYSTEM of Delaware Application .lanuary z, rose, Serial No. 57,315

(Crass-4e) 2 Claims.

This invention relates to control systems and particularly to a system for controlling the relative humidity of a space during'the winter heating months, and also the temperature thereof.

Many systems have been provided in the past for humidifying spaces or rooms to maintain a predetermined relative humidity therein during thewinter to provide-comfort and still decrease the load on the heating plant. However, these prior humidifying systems are subject to the objection that upon decreases in outdoor temperature the moisture or water vapor placed in the spaces or rooms by the humidifying means condenses on the relatively cold windows and walls, thereby causing frosting of the windows and injury to the walls.

Itis, therefore, the prime object of this inven tion to provide a humidity control system wherein moisture may be admitted to a room or space but wherein the moisture content of the air within the space or room is decreased when the outdoor temperature decreases, thereby preventing condensation from taking place on the windows and the outside walls of the Space.

It is found that changes in outside tempera.- tures are reflected in changes in the room or space temperatures adjacent the windows of the space or room. In other words, a decrease in outside temperature causes a decrease in the spacetemperature adjacent the windows. It is known that with a given amount of moisture contentin the air a decrease in the air temperature consequently causes an increase in the relative humidity. Therefore, since the temperature of the air o'f-the space adjacentthe windows is decreased the relative humidity of that air is increased. By placing a humidity responsive device adjacent the window so as to be subject to this increase in relative humidity caused by a decrease in outdoor temperature and having this humidity responsive .device control the humidifying means of the space the relative humidity of the space is thereby reduced when the outdoor temperature decreases. This effectively prevents frosting of 'the windows and condensation of moisture on the outside walls of'the space. It is. therefore,- an object of this invention to provide a humidity control system wherein the humidity responsive device is located adjacent a window of the space to control the space humidifying means whereby to decrease the introduction of moisture into the space when the outdoor temperature decreases.

present adjacent windows because the reduction in temperature of suchair causes its weight per volumeter unit to increase and in order to get an extremely accurate control it is desirable to place the humidity responsive device not only adjacent to the window but below the window so that it, will respond more rapidly to changes in outside temperature conditions. As is apparent, the humidity responsive device should not be located underneath a window that has a radiator in front of it. It is, therefore; an object of this invention to provide a humidity control system.

space is likewise decreased. Therefore, it is an-' other object ,of this invention to increase the dry bulb temperature of the space as the relative humidity is decreased whereby a substantially constant effective temperature is maintained. This may be accomplished by having the humidity responsive device, which is located adjacent the window or underneath the same, adjust or compensate the room thermostat to increase the dry bulb temperature when the relative humidity of the space is decreased by the increase in relative humidity adjacent the window. The manner in which this mode of opera- It is also found that downward flowof airis 55 tion is-accomplished also forms objects of this invention.

It is also foundthat the relation between the breathing line temperature and the floor line temperature of a space varies in accordance with temperature conditions existing outside of the space. Specifically, upon decreases in outside temperature the floor line temperature also decreases. This principle may also be utilized in this invention by adjusting or compensating a humidity controller responsive to the relative humidity in the space by a thermostatic mechanism responsive to the floor line temperature. Therefore, another object of this invention is to provide a humidity control system wherein the humidity responsive device is adjusted or compensated-in accordance with floor line tempera-- tures, whereby the relative humidity of the space or room is decreased'as the outdoor temperature decreases to prevent frosting of the windows. The same mode of operation may be accomplished by locating the thermostat adjacent or thermostatic means located adjacent the door line or a thermostatic means' located adjacent or underneath the window, adjust or compensate the room thermostat in such a manner as to increase the dry bulb temperature of the space as the relative humidity of the space is decreased in accordance with decreasing floor line temperatures or decreasing temperatures adjacent or underneath the window. The manners in which this effective temperature regulation is obtained also form objects of this invention.

It is also an object of this invention to provide a humidity control system wherein the humidity responsive device itself is located adjacent the floor of the space whereby the relative humidity of the space is decreased as the outdoor temperature decreases. The theory upon which this object is predicated is based on the fact that as the floor line temperature decreases the relative humidity adjacent the floor increases This huniidity responsive device may also adjust or compensate a room thermostat to maintain substantially constant effective temperatures.

Other objects and advantages will become apparent to those skilled in the art upon referenceto the accompanying specification, claims and drawings, in which drawings:

Figure 1 is a diagrammatic illustration of one form of my invention as applied to a hot air heating system for a space;

Figure 2 is a wiring diagram of that form of my invention shown in Figure 1;

Figure 3 is a diagrammatic showing of another form of my invention as applied to a unit heater for conditioning a space;

Figure 4 is a wiring diagram of that form of my invention shown in Figure 3;

Figure 5 is a diagrammatic showing of another form of my invention which accomplishes the same results mechanically as are accomplished electrically in Figure 3;

- Figure 6 is a view showing the thermostat utilized in Figure 5;

Figure 7 is a -view showing the humidity responsive device utilized in Figure 5;

Figure B is a diagrammatic illustration of another form of my invention, and

Figures 9 and 10 are diagrammatic illustrations of still other forms of my invention.

Referring now to Figure 1, a room having a window II is designated at Hi. This room I 6 may be heated by a hot air furnace designated at l2 which may in turn be fired by a gas burner l3 receiving a supply of gas from a gas ipe l4 under the control of a valve l5. The valve l5 may be controlled by an electric motor l6 of the type shown and described in Willis H. Gille, Patent No. 2,032.658 Mar. .3, 1936.. The gases of combustion may be conveyed from the hot air furnace i2 by a flue I! to a stack It. The heated air-may be conveyed from the hot air furnace l2 through a duct or conduit Hi to the space It) to be heated. Located in the bonnet of thehot air furnace i2 is a humidifying device which may take the form of a spray 20.which receives its supply of water from a pipe 2| under the control of a valve 22. The valve 22 may be operated by a motor 23which is in all respects similar to the motor l6 and which is shown and described in the above referred to Gille patent.

Located in the room I0 is a thermostat 25 and also located in the room l0 adjacent the window and preferably underneath the window II is a humidity responsive device 26. The thermostat' 25 and the humidity responsive device 26 are connected by suitable conduits 21 and 28 to the motor is for controlling the operation of the gas valve l5. The humidity responsive device 26 is suitably connected by a conduit 29 to the motor 23 for controlling the operation of the water valve 22.

The manner in which the thermostat 25 and the humidity responsive device 26 control the gas valve I5 and the water valve 22 is diagrammaticall illustrated in Figure 2. The thermostat 25 is shown to comprise a bimetallic ele'- ment 30 for operating a slider 3| with respect to a potentiometer coil 32, the arrangement being such that upon a decrease in room temperature the slider 3| is moved to the left in the direction indicated by the character C and upon an increase in room temperature, the slider 3i is moved to the right with respect to the potentiometer coil 32 in the direction indicated by the'character H.

The humidity responsive device 26 may comprise a pivoted lever 33 which is adjusted by means of an adjusting screw 34. Pivoted lever 33 carries one end of a humidity responsive element 35 and the other end thereof is connected to a lever 36 fulcrumed by a knife-edge 31. The lever 36 is urged in a counter-clockwise direction about its fulcrum 31 by means of an adjustable tension spring 38. The lever 36 is operatively connected to a carrier 39, preferably formed of insulating material, which carries sliders 40 and 4| and is adapted to move these sliders with respect to potentiometer. coils 42 and 43, respectively. The arrangement is such that upon an increase in space relative humidity, the humidity responsive element 35 expands to allow movement of the sliders 40 and 4! upwardly with respect to the potentiometer coils 42 and 43 in the direction indicated by the character W and upon a decrease in relative humidity, the humidity responsive element 35 contracts .to move the sliders 40 and 4| downwardly with respect to the potentiometer coils 42 and 43 in the direction indicated by the character D. 'The adjusting screw 34 and the adjustable tension spring 38-provide a means for calibrating and adjusting the setting of the humidity responsive device 26.

The valve I5 for-controlling the supply of gas to the hot 'air furnace I2 isoperated by means 'of a valve stem 45, the valve being biased at gear and beinglocated in the slot 48. It is therefore seen that a spring pressed lost motion connection 'exis-ts between the beveled gear 50 and the valve stem 45. The beveled gear 53 is operated by another beveled gear 5| mounted on a shaft 52 of the motor l6. The shaft 52 carries a gear 53 which is operated through a reduction gear train, generally designated at 54, by a motor rotor 55. The motor rotor 55 is operated by field windings 56, 5! and 58. The field winding 56 is of suflicient strength to maintain the valve in any number of given positions against the action of the valve biasing spring 46 but field winding 56 is not of suflicient strength to overcome the valve biasing spring 46 to move the valve towards an open position. Field winding 51 is opposite in action to the field winding 56 and when both of field windings 59 which meshes with a beveled gear 60 which in turncarries an abutment member 6i, preferably formed of insulating material. ment member 6| operates a slider 62 with respect to a balancing potentiometer coil 63, the arrangement being such that upon opening movement of the valve I5, the slider 62 is moved .to the right with respect to the potentiometer coil 63 and upon closing movement of the valve I5, the slider 62 is moved to the left with respect to the balancing potentiometer coil 63.

The abutment member 6I car'ries' fingers 64' and 65 which are adapted to engage contacts 66 and 61 to move these contacts 66 and 61 out of engagement with contacts 66 and 69, respectively upon extreme closing or opening movement of the valve I5.

fully hereafter, the contacts 66, 61, 69 and 69 form limit switches for the motor I6.

The motor I6 also contains a relay mechanism which may comprise an armature I piv-v otally mounted at II. A switch arm I2 is carried by the armature I6, insulated therefrom,

and operated hereby with respect to contacts I3and I4. he armature I0 is moved about its pivot II by means of relay coils I5, I6, I1 and I9. .When the relay coil I is energized more than the relay coil I6, the switch arm I2 is moved into engagement with the contact 14 and when the relay coil 16 is energized more than the relay coil I5, the switch arm I2 is moved into engagement with the contact I3.

Power is supplied to the motor I6 by means of a step-down transformer I9 having a primary 80 connected to some source of power, not shown, and a secondary 8|. One end of the secondary BI is connected by wires. 62 and 63 to one end of relay coil IS-and the other end of the secondary 8I is connected by wires 64 and-85 to one end of the relay coil I6. The other ends of the relay coils I5 and I6 are connected together by means of'wires 86 and 81. The junction'of wires 86 and 81 is connected by wires 88, 99, 90, 9| and 92 to the slider 62 of the balancing potentiometer, to the The abut- 99, wires I00 and IM and resistance I02 to the left-hand end of balancing potentiometer coil 63. The junction of wires I00 and IOI is connected by wires I03 and m to the left-hand end of potentiometer coil 32 of the room thermostat and the junction of wires I03 and I04 is connected by a wire I05 to the upper end of potentiometer coil 42 of the humidity responsive device .26. Thus, it is seen that the upper ends of the relay coils I5 and I6 and the sliders 62, 3| and are connected together, that the lower end of the'relay coil I5, the right-hand end of balancing potentiometer coil 63, the right-hand end of potentiometer coil 32 and the lower end of the potentiometer coil 42 are connected together, that the'lower end .of the relay coil I6, the left-hand end of balancing potentiometer ,coil 63, the left-hand end of potentiometer coil 32, and the upper end of potentiometer coil 42 are connected together, and that the lower ends of the relay coils I5 and I6 are connected across the secondary M of the step-down transformer I9. It is therefore seen that the secondary 8| of the step-down transformer I9, the relay coils I5 and I6, the balancing potentiometer, the room thermostat potentiometer and the humidity responsive device potentiometer are all connected in parallel. The left-hand end of secondary'BI is connected by means of wires I06 and I0I to one end of fieldwinding 56 and the other end of 'field wind- As will be pointed out more ing 56 is connected by a wire I08 to the limit switch. contact 66. The limit switch contact 66 cooperating with the contact 66 is connected by III a resistance I09 and a wire III] to the junction of wires 84 and 85. The junction of wires I06 and I01 is connected by a wire III to the switch arm 12 operated by the relay armature I0. The contact .14, cooperating with the switch arm I2, is connected by a wire II2 to one end of relay coil 1! and the other, end thereof is connected by a wire H3 to one end'pf fieldwinding 56. The

other end of field winding 58 is connected by a wire I to the limit switch contact 69. The limit switch contact 61, cooperating with the contact 69, is connected by a wire 5 to the junction of resistance I09 and the wire H0. The contact wire H8 to the junction of field winding 56 and slider 3| of the room thermostat 25 and to the slider 40- of the humidity responsive device 26. The junction of wires 62 and 93 is connected by a protective resistance 93 and wires 94 and 95 to the right hand (and of balancing potentiometer coil 63. The junction of wires 64 and 95 is-connected by wires 96 and 91 to the righthand end of potentiometer coil 320i the room thermostat 25 and the junction of wires 96 and 97 is connected by a wire 99 to the lower end of the potentiometer coil 62 of the humidity responsive device 26. The junction of wires 84 and 85 is connected by a protective resistance the wire I09.

The operation of thestructure just described is as followsrThe sliders 3|, 40 and 62 are in a mid-position with respectto their potentiometer coils 32, 42 and 63, respectively and,-as a result thereof, the switch arm I2 is in a mid-position with respect to the contacts I3 and I4 and the valve I5 is in half open position. With the parts in this position, a circuit is completed from the secondary 8 I through wires I06 and I01. field winding 56, wire I08; limit switch contacts 66 and 68, resistance I09, wires H0 and 84 back to the secondary M. This circuit causes energization of field winding 56 to maintainthevalve I5 in its half open position. Assume for the present that the slider 40 is maintained in the mid-position with respect to its potentiometer coil 42. ment of slider 3i to the left with respect to the potentiometer coil 32 in the direction indicated by the character C, upon adecrease in space temperature. causes partial short-circuiting of the relay coil I6 and by reason of the parallel rela- .to the secondary 8| tion of the relay coil I6 to decrease and the energization of relay coil I6 to increase. Due to this unbalanced relationship of the relay coils 'I5and 16. the switch arm 12 is moved into engagement with the contact 14 to complete a circuit from tionship set out above, this causes the energiza-' spect to its potentiometer coil 32; When the- I slider 62 has moved sumciently far to the left with respect to-balancing potentiometer coil 63 so as to-rebalance the energization of the coils I5 and I6, the switch arm I2 is moved out of the secondary 8| through wires I06 and III,,

switch arm I2, contact I4, wire: 2, relay coil 11, wire II3, field winding 58, wire I I4, limit switch contacts 69 and .61 and wir'es H5, I "and 84 back Completion of this circuit causes energization of the fleld'winding' 56 and sincethe field winding 56 is energized inthe man-- ,ner pointed out above,the valve I5 is moved towards an open position against the bias of the spring 46 to supplyimore gas to the burner I3 to supply more heat to the space, I8.

sition shown in the drawing to cause deenergization of the field winding 51. Deenerglzation of field winding 51 prevents further closing move Movement of the valve I5 towards an open position in this manner causes right-ha d movement of slider 62 with respect to the potentiometer coil 63.. 'Movement of slider 62 to the 'right with respect to the balancing potentiometer coil- 63 causes partial short-circuitingof the relay coil and due tothe parallel relationship pointed out above, this partial short-circuit of relay coil .15 decreases the energization thereof and increases the energization of relay.coil 16,-it being movement of slider 3| with respect to its potenment of the valve I5 by the spring 46 and when the field winding 56 is maintained energized in the manner pointed out'above, the valve I5 is;

maintainedin its newly adjusted position.

By reason of the aboveconstructi on, the valve I5 is modulated or proportioned between'closed and opened positions in accordance with changes in space temperature whereby substantially conthe space I8.

.stant space temperatures are maintained within Movement-of the valve I5 to a full openposition causes the finger 65 to engage the contact 61 to separate, the limit switch contacts 61 and 69 to break the circuit through the field winding 58, whereby the coil 58. is deenergized when the valve has reached. its full open position. Likexwise', when the valve I5 is moved to a full closed tiom'eter coil 32. When the slider 62 has been moved sufliciently far to the right with respect to balancing potentiometer coil 63, to rebalance the energizations of the relay coils l5 and I6, the switch arm 12 is moved out of engagement with the contact I4 to the mid-position as shown in the drawing. This causes breaking of thecircuit through the field winding 58 to prevent further 6 opening movement of the valve l5 and since the field winding 56 is maintained energized in the manner pointed out above, the valve I5 will be maintained-inthe new position. J

Upon an increase in space temperature, the slider 3| is mbved to the right with respect to potentiometer coil 32 in the direction indicated .wire II6, relay coil I6, wire II I, field winding 51,

wires H8 and I88,,limit switch contacts 66 and 68, resistance I89 and wires H0 and 84 back to the secondary 8|. This-causes energization of the field winding 61 which neutralizes the action of field winding 66 to allow thespring 46 to move the valve I5 towards a closed position. Movement of-the valve I5 towards a closed position decreases the amount of gas supplied to the burner I3 and consequently decreases the amount of heat delivered to the space Ill.

Movement of valve I5 towards a closed position causes left-hand movement of slider 62 with respect to the balancing potentiometer coil 63 which movement causes partial short-circuiting of the relay coil I6 to decrease the energization thereof and increase the enerigization of tlierelay coil I5, it being remembered that the energization of relay coil I5 was decreased and the energization of the relay coil I6 was increased by reason of the right-hand movement of slider 3| with reposition, the finger 64 breaks contact between the reason of the resistance I02 which is not engaged j by the slider 62 of the balancing potentiometer.

Therefore, the balancing potentiometer'cannot entirely rebalance the energizations of the relay coils I5 and 16 before the valve I5'is completely closed, The specific manner in which this is carried out is pointed out in the above referred to Gille patent.

Since the circuit through the field winding 56 is broken when the valve I5 is moved to a complete closed position, it is necessary to provide the above-referred to lost motion connection between the motor I6 and the valve stem 45. Upon a call for heat by the room thermostat 25 to cause energization of the field winding 58, the motor I6 is placed in operation to take up the lost motion provided by the slot 48, this movement -of the motor being permitted by reason of the fact that during this preliminary movement of the motor field winding 58 does not have to act against the valve biasing spring 46. When the lost motion whereby the combined action of field windings 56 v and 58 mayovercome the spring 46 and move the valve to an open position as demanded by the room thermostat 25.

The resistance I88 is placed in the circuits through the field windings 66 and 51 to compensatefor the decrease in resistance caused by the opposed or bucking action of the coils 56 and v 51, all of which is clearly pointed out in the above referred to'Gille applcation. It will also be noted that the circuits th ugh the field windings 51 and 58 pass through the relay coils I8 and "II respectively, whereby the switch arm 12 is held in engagement with the contacts I3 and 14 with a substantial force to prevent relay chatter from occurring at these points. t The motor 28 for operating the water ,valve 22 is exactly the same as the motor I6 for operating the gas valve I5 and the mode of operation thereof is also exactly the same. the motor 28 corresponding to the parts of the The various parts of motor I6 are indicated by like primed reference characters and therefore a complete description of the structure and mode of operation of the motor 23 is not considered necessary. The upper ends of the relay coils I5 and I6 are connected by wires 86', 81, 88' and 96' to the slider II of the humidity responsive device 26. The lower end of the relay coil I5 is connectedby wires 83', protective resistance 93' and wires 94' and 96' to the upper end of the potentiometer coil 43 of the humidity responsive device 26. In a like manner, the lower end of the relay coil 16' is connected by a wire 85', a protective resistance 99' and wires I06 and I03 to the lower end of the potentiometer coil 43 of the humidity responsive device 26. It therefore follows that upon a decrease in relative humidity within the space III so as to move the slider 4I downwardly with respect to the potentiometer coil 43, as indicated by the character D, the valve 22 is moved towards an open position to supply more moisture to the air within the space III, the amount of opening movement of the valve being dependent upon the decrease in the relative humidity. Likewise,

upon'an increase of relative humidity within the space ID, the slider 4| is moved upwardly with respect to the potentiometer coil 43 in the direction indicated by the character W to move the water valve 22 towards a closed position, the amount of closing movement being dependent upon the amount of increase in space relative humidity. In this manner, the supply of water Vapor to the space It is decreased. -By reason of this construction, the percent of relative humidity within the space I is maintained at a substantially constant value so long as the outdoor temperature remains constant.

As pointed out above, decreases in outdoor temperature cause decreases in space temperature adjacent the window II and a decreasein space temperature at this point will cause an increase in the relative humidity at this point. By locating the humidity responsive device 26 adjacent the window so as to respond to this increase in the percent of relative humidity,

' and condensation of moisture on the walls. Al-

though the humidity responsive device responds to these changes readily when it is located adjacent the window, the response is more direct and more accurate when the humidity responsive device is located beneath the window and concreases in the percent of .relative humidity. Therefore, :the potentiometer coil 42 and the slider 44 of the humidity responsive device 25 are connected in parallel with the potentiometer coil 32 and slider 3| oi the thermostat 25. With the slider SI of the thermostat 25 in the midposition shown in the drawing, an increase in relative humidity adjacent or beneath the window II' causes upward movement of the slider 40 sequently it is desirable to place the humidity -resp0nsive device 26 below the window when there is no radiator in front of the window.

Upon an increase in relative humidity adjacent the window as caused by decreases in outdoor temperature, which affects the humidity responsive device 26 to decrease the percent of relative humidity within the space ID, the efiective temperature of the space It is also decreased. In order to maintain the effective temperature of the space III at a substantially constant value, it is necessary to increase the dry bulb temperature in accordance with the dewith respect to the potentiometer coil. 42. This upward movement causes partial short-circuitin of the relay coil I6 to decrease the energization thereof and increase the energization of relay coil I5 thereby causing opening movement of the valve I5, the amount of opening movement being dependent upon the increase in relative humidity of the space adjacent'or beneath the window II. In this manner, the amount of heat supplied to the space I0 is increased in accordance with the decrease in relative humidity existing withinthe space III. device 26 and the thermostat 25 control theoperation of the gas valve IS, a substantially constant efiective temperature is maintained within the space III at all times and the relative humidity within the space. III is maintained at such a value whereby frosting of the windows and condensation of moisture on the walls are effectively prevented.

Referring now to Figure 3 of the drawings, 1- have shown a modified form of control system as applied to a unit heater generally designated at I2I). The unit heater I26 may comprise a radiator I2I, receiving a supply of heating fluid such as steam through a riser I22 and a header I23 from a boiler I24. The boiler I24 may be fired in any suitable manner as by means of an oil burner I25. Th gases of combustion may pass from the boiler I24 through a flue I26 into a chimney I21. The supply of heating fluid to the radiator. I2I may be controlled by means of a valve I28 which in turn is positioned between an opened and closed position by means of the motor it which is in all respects the same as the motor I6 for operating the gas valve I5 of Figure 1. The expended heating fluid may be returned from the radiator I2I through a riser I29 and a header I30 to the boiler I26. Also located within the unit heater I26 is a humidifying means which may take the form of a spray I3I which receives its supply of water through a' pipe I32 under the control of a-water valve I33. The water valve I33 is operated by means of a motor 23 which is identical to the motor 23 of Figures 1 and 2.

Located within the space I0 is a thermostat I34 which. is in all respects the same as the thermostat 25 of Figures 1 and 2. Also located within the space It is a humidity responsive device I36 which is similar to the humidity re-- sponsive device 26 of Figures 1 and 2. This form of the invention contemplates the use of a thermostat I36 also located within the space It for adjusting or compensating the control by the thermostat I34 and the humidity responsive device I35. The thermostat I34 and the thermostat i36 are connected by suitable conduits I31 and I36 to the motor I6 for controlling the supply of heating fluid to the radiator I2 I. The humidity responsive device I35 and the thermostat I36- are connected by suitable, conduits I39 and I40 Since both the humidity responsive upon a decrease in space temperature, slider 3| v is moved to the left.

The humidity responsive device I35 is in some manners similar to the humidity responsive device 26 of Figures 1 and 2 and is shown to comprise a lever 33 adjusted by an adjusting screw 34 to which one end of a humidity responsive element 35 is connected. The other end of the humidity responsive element 35 is connected to a lever 36 fulcrumed at 31, the lever being urged in a counter-clockwise direction by an adjustable tension spring 38. Instead of operating a plurality of sliders as in Figures 1 and 2, the lever 36 operates a single slider I42 with respect.to a potentiometer coil I43, the arrangement being such that upon increases in relative humidity,

the slider I42 is moved upwardly in the direction .indicated by the character W and upon decreases in relative humidity, the slider I42 is moved zdownwardly in the direction indicated by the character D.

The compensating or adjusting thermostat I36 may comprise a bimetallicelement I45 for operating an arm I46. The arm I46 is operatively connected to a carrier I41 preferably formed by insulating material'which carries sliders I48 and I49. The sliders I48 and I49 are moved with respect to potentiometer coils I50 and I5I, respectively, upon changes in floor line temperature affecting the bimetallic element I45. The arrangement is such that upon an increase in floor line temperature, the sliders I48 and I49 are moved to the right with respect to the potenti- ,ure 2 and therefore it follows that upon an in- IS is crease in space temperature, the valve 7 moved towards closed position to decrease the supply of heat to the space I0 and upon a decrease in space temperature, the valve I5 is moved towards open position to increase the supply of heat to the space I0. In each instance, the

amount of opening or closing movement of the valve I5 is determined by the increase or decrease of the space temperature. The slider I42 and the potentiometercoil I43 of the humidity responsive device I35 are connected to the relay coils I5 and I6 in exactly the same manner as the potentiometer coil 43 and the'slider M are connected to the relay coil I5 and I6 of Figure 2. Therefore, it follows that upon an increase in space relative humidity, the valve I33 is moved towards a closed position and upon a decrease in space relative humidity, the valve I33 is moved towards an open position, the amount of opening and closing movement of the valve I33 being dependent upon the deviation of the space relative humidity from the desired value.

The left-hand end of potentiometer coil I50 of compensating or adjusting thermostat I36 is connected by wires 98' and 91' to the upper end of the potentiometer coil I43 of the humidity responsive device I35. In a like manner, the righthand end of potentiometer coil I50 is connected by wires I05 and I04 to the lower end,of the potentiometer coil I43 and the slider I48 associated with the potentiometer coil I50 is connected by wires 92' and 9If to the slider I42 associated with the potentiometer coil I43. It is therefore seen that the potentiometer coil I50 and slider I48 of the compensating or adjusting thermostat I 36 are connected in parallel with the potentiometer coil I43 and the slider I42 of the humidity responsive device I35. I

As pointed out above, it is found that upon a decrease in outside temperature, the floor line temperature is also decreased. Also, as pointed out above, sufficient decrease in outside temperature ordinarily causes frosting of the windows and condensation of moisture on the walls. By placing the compensating oradjusting thermostat I36 adjacent the floor line so as to respond to these decreases in floor line temperature as caused by decreases in outdoor temperature and by having the compensating or adjusting thermostat I36 adjust or compensate the control of the water valve I33 by the humidity responsive device 35, a control is, obtained whereby frosting of the windows and condensation of moisture on the walls is effectively prevented. Assume that the slider I42 is in such a position with respect to the potentiometer coil I43 so as to supply the correct amount-of moisture to the space I0 and that the outside temperature thereupon decreases, this decrease in outside temperature causes a decrease in floor line temperature and the bimetallic element. I45 responding to this decrease in floor line temperature causes movement of the slider I48 to the left with respect to the potentiometer coil I50. This left-hand move-' ment causes partial short-circuiting of the relay coil I5 to decrease the energization thereof and increase the energization of the relay coil I6. This causes movement of water valve I33 towards a closed position to' decrease the supply of moisture to the space I0 whereby the relativehumidity of the space I0 is decreased and frosting of the windows and condensation of moisture on the walls is prevented. If the outdoor temperature should thereafter rise, the floor line temperature of the space I0 would likewise rise and the bimetallic element I45 responding to this increase in floor line temperature causes movement of slider I48 to the right with respect to the potentiometer coil I50. This movement causes partial short-circuiting of the relay coil I6 to decrease theenergization thereof and increase the energizati'on of relay coil I5 to move the water valve I 33 towards an open position. In this manner, the percent of relative humidity within the space I0 is increased upon increases in outdoor temperature. By reason of this construction shown in Figures 3 and 4, the space relative humidity is maintained at a desired value but upon a decrease in outdoor temperature which would normally cause frosting of the windows and condensation of moisture on the walls, the percent of relative humidity within the space I0 is decreased to absolutely prevent this undesirable function.

A decrease in relative humidity of the space I0 brought about in the above manner causes a decrease in the effective temperature within the space I0. In order to maintain the effective aaeaoci temperature of the space I constant, the dry and the sliders I49 and 3| associated with the potentiometer coils I5I and I32, respectively. also being connected together.

Assume that the slider 3| is so positioned with respect to the potentiometer 001132 to maintain the valve I28 in the correct position to maintain the space temperature at the desired value. Up-

on a decrease in outdoor temperature which through the above described control system decreases the relative humidity within the space III, the slider I49 is moved to the left with respect to the potentiometer coil I5I. This left-hand movement causes partial short-circuiting of the relay coil 16 to decrease the energization thereof and increase the energization of the relay coil 15. This causes movement of the valve I28 towards an open position to supply additional heat to the space I0 whereby the dry bulb temperature of the space I0 is increased. Upon an increase in outdoor temperature, the floor line temperature of the space I0 is increased to cause movement or the slider I49 to the right with respect to potentiometer coil I5I which causes partial shortcircuiting of the relay coil to decrease the energization thereof and increase the energization of relay coil 16. This unbalanced relationship of coils 15 and 16 causes closing movement of the valve I28 to decrease the supply of heat V valve I 33 is exactly the same as that shown in Figure 4; Referring now to Figure 6, the space thermostat I55 is shown to comprise a bimetallic element I6I for operating a slider I62 with respect to a potentiometer coil I63. The potentiometer coil I63 is mounted on a slidable bracket I64 which is urged to the right by a compression -spring I65 suitably adjusted by an adjusting screw I66. The-bracket I64 is urged to. the left by a bellows I61 which is connected by the capillary tube I58 to the floor line bulb I51. Upon a decrease in floor line temperature, the bellows I61 contracts and spring I65 moves the potentiometer coil I63 to the right with respect to the slider I62 and upon an increase in floor line temperature, the bellows I61 expands and the potentiometer coil I63 is moved to the left with respect tothe slider I62. The bimetallic element I6I is so arranged that it moves the slider I62 to the left upon decreases in space temperature and to the right upon increases in space temperature as indicated by the characters C and H respectively. The potentiometer coil I63 and the slider I62 are connected to the relay coils 15 and 16 in exactly the same manner as the potentiometer coil 32 and slider 3I are connected in Figure 4. A decrease in floor linetemperature causes movement of the coil I 63 to the right with respect to the slider I62 and has the same effect as movement of the slider I 62 to the left with respect to the coil I 63 under the action of bime-.

tallic element I6I both of which cause opening movement of the valve I26 to increase the supply of heat to the space I0. Likewise, aniincrease in floor line temperature which causes left-hand movement of coil- I63 with respect to the slider I62 has the same efiect as movement of slider I62 to the right with respect to the potentiometer coil I63, caused by an increase in space temperature, both of which cause movement of the valve I26 towards a closed position. In 'this'manner,

the thermostat I55 is adjusted or compensated the dry bulb temperature of the-space I0 is increased upon a decrease in outdoor temperature whereby a substantially constant effective temperature is maintained within the space I6 and frosting of the windows and condensation of moisture on the Walls is prevented.

In Figures 3 and 4, I have shown the space thermostat I34 and the space humidity responsive device I35 to be electrically adjusted or com pensated by the floor line thermostat I36. However, the same mode of operation and the same results may beobtained by mechanically adjusting the space thermostat I35 and the space humidity responsive device I35. Such construction is diagrammatically illustrated in Figure 5 wherein the space thermostat is designated at I and the space humidity responsive device is designated at I56, these devices being connected by suitable conduits I31 and I39 to the motors I6 and 23 for controlling the supply of steam andv the supply of humidifying water to the unit heater I20 as in Figure 3; The space'thermostat I55 is shown to be adjusted by a bulb I51 connected thereto by the capillary tube I58 and the humidity responsive device I56 is shown to be adjusted or compensated by a bulb I59 connected thereto mechanically in accordance with floor line temperatures to increase the supply of heat to the space I' 0 as the floor line temperature decreases and to decrease the amount of heat to the space I0 as the floor line temperature increases.

In Figure 7, I have'shown the humidity responsive device I56 to be substantially the same as the humidity responsive device I35 of Figures 3 and 4, provision being made in Figure '7 however for longitudinal movement of the potentiometer coil I43. The potentiometer coil I43 is shown to be mounted on a bracket I68 and to carry a yoke I60 which is engaged by a pivoted lever I10. The lever I10 is urged in a clockwise direction about its pivot by means of a compression spring III which may be adjusted by an adjusting screw I12. The lever I10 may be urged in a counter-clockwise direction'by a bellows I13 which is connected by the capillary tube I60 to the floor line bulb I59, the arrangement being such that when the floor line temperature increases, the potentiometercoil I43 is'moved upwardly and when the floor line temperature decreases, the potentiometer coil I43 is moved downwardly. The potentiometer coil I43 and the slider I62 of Figure -'1 are connected to the relay coils 15' and 16' in exactly the same manner as in Figure 4. Movement of the potentiometer coil I43 downwardly with respect to the slider I42 upon a decrease in floor line tempera-' ture has the same. effect as upward movement coil I43 both of which cause partial short-circuiting of the relay coil I5 to decrease the energization thereof and increase the energization of relay coil 15. This causes movement of valve I33 towards a closed position. Upon an increase in floor line temperature, the potentiometer coil I43 is moved upwardly with respect to the slider I42 which has the same eflfect as moving the slider I42 downwardly with respect to the potentiometer coil I43 both of which cause partial short-circuiting of the relay coil 15' to decrease the energization thereof and increase the energization of relay coil I5. This causes opening movement of the water valve I33 to increase the amount of moisture delivered to the space III. In this manner, a decrease in floor line temperature as caused by a-decrease in outdoor temperature causes closing movement of the water valve I33 to decrease the supply of-moisture to the space I and an increase in the floor line temperature as caused by an increase in outdoor temperature causes opening movement of the water valve I33 to increase the supply of moisture to the space I0. Therefore, by reason of this construction, the humidity responsive device I56 is mechanically adjusted to decrease the relative humidity within the space ID as the outdoor temperature decreases whereby frosting of the windows and condensation of moisture on the walls is eifectively prevented.

Since the temperature adjacent the windows orunderneath the windows decreases as the outdoor temperature decreases, the adjusting or compensating thermostat I35 of Figure 3 or the adjusting or compensating bulbs I51 and I55 of Figure 5 may equally as well be placed adjacent or underneath the windows to effect the same control, as is accomplished in Figures,3 and 5 wherein the thermostat I35 and the bulbs I51 and I59 are located adjacent the floor and it is within the contemplation of this invention to so locate these devices. The control afforded by such a location of these devices would compare favorably with the control obtained by the location of the devices as. illustrated in Figures 3 and 5. Accordingly, in Figure 9 the compensating thermostat I35 which compensates or adjusts the thermostat I34 and the humidity responsive controller I35 is shown to be located under the window II. The conduit connections between the controllers I34, I35 and I35 and the valve motors l5 and 23 of Figure 9 are designated by the same reference characters as in Figure 3. The wiring arrangement of Figure 4 is utilized in Figure 9.

Since the floor line temperature decreases in accordance with outdoor temperature and since the relative humidity increases upon decreases in temperature, the relative humidity adjacent the floor of the space Iii will increase upon decreases in outdoor temperature. It is therefore possible to obtain a satisfactory operation of a humidifying means by locating the humidity responsive device adjacent the floor to respond to increases in relative humidity of the space adjacent the fioor as caused by increases in outdoor temperature. Consequently, in Figure 8, I have disclosed a humidity responsive device 25 located adjacent the floor for controlling the operation of the motor 23 and being suitably connected apaaui 7 thereto by a conduit 25. The motor 23 controls a water valve 22 in a humidifying device I15 located within or serving the space ll. Upon a decrease in floor line temperature as caused by a decrease in outdoor temperature, the. relative humidity of the space adjacent the floor is increased and the humidity responsive device 25 responds to this relative humidity adjacent the floor to cause closing movement of the valve 22 to decrease the amount of moisture being supplied to the space I5 whereby frosting of the windows and condensation on the walls is eifectively prevented. The manner in which the humidity responsive device 25 controls the motor 23 of the water valve 22 is exactly the same as that illustrated in Figure 2.

The humidity responsive device 25 which is located adjacent the floor in Figure 8 may also compensate or adjust a room thermostat in exactly the same manner as the humidity device 25 of Figures 1 and 2 compensate or adjust the space thermostat 25 of Figures 1 and 2 and a satisfactory control of the effective temperature of the space may thereby be obtained. This arrangement is shown in Figure 10 wherein the humidity responsive device 25 which adjusts or compensates the thermostat 25 and which controls the valve motor 23 is located adjacent the floor. The conduit connections between the controllers 25 and 25 and the valve motors I5 and 23 are designated by the same reference characters as in Figure l. The wiring arrangement of Figure 2 may be utilized in Figure 10.

Although I have disclosed for purposes of illustration in this application a modulating or proportioning type of system for accomplishing relative humidity and effective temperature control, this invention is applicable to the off and on type of control system and such off and on manner of operation is contemplated within this invention. Although for purposes of illustration I have disclosed various forms of my invention, other forms thereof may become apparent to those skilled in the art and consequently this,

invention is to be limited only by-the scope of the prior art and appended claims.

I claim as my invention: v

. 1. In a control system for a space, the combination of humidifying means for the space, heating means for the space, means responsive to space temperature for controlling said heating means, and means responsive to the relative humidity in the space which is aifected by conditions outside ofthe space for controlling said humidifying means and additionally controlling said heating means.

2. In a control system for a space having a window, the combination of humidifying means and heating means for the space, means responsive to space temperatures for controlling said heating means, the relative humidity of the space adjacent the window varying in accordance with changes in the condition outside of the space, and means located adjacent the window and responsive to the space relativmhumidity adjacent the window for controlling said humidifyingmeans and adjusting the temperature re sponsrve means. i

GEORGE D. KINGSLAND. 

